The Renwick Gallery signs continue to attract attention — but not the kind the museum is seeking.

Although the museum has enjoyed record-setting crowds since reopening last month, the illuminated red signs, placed over the building’s main door and at street level next to the gallery, are still being criticized by federal agencies.

The National Park Service is the latest, joining the National Capital Planning Commission and the U.S. Commission of Fine Arts to charge the Smithsonian Institution with skirting preservation laws. Although the NCPC and the CFA are asking the world’s largest museum complex to bring the signs to their boards for approval, the Park Service is appealing to the Smithsonian’s wallet, suggesting that the institution’s failure to comply jeopardizes a $335,000 grant awarded in 2010.

In a Dec. 10 letter to Smithsonian Secretary David J. Skorton, Park Service National Capital Region Director Robert Vogel noted that the signs — described as “incompatible with the historic character” of both the building and the neighborhood — were not vetted and thus do not comply with the grant contract. The letter was sent to Skorton because the Renwick is part of the Smithsonian American Art Museum.

Vogel’s letter is the latest salvo in a simmering battle between city leaders and the Smithsonian, a fight that critics fear has serious and long-term consequences for District development. Some think that Smithsonian officials are playing fast and loose with a complicated web of preservation laws that govern federal, District and private property. Some suggest that the reason Smithsonian officials did not seek approval is that they knew they would not get it. And others worry that the Smithsonian’s intransigence over signs signals an overarching attitude that will be applied to larger projects on the horizon.

But all the critics agree that the signs disrupt the dignity of the historic block, which includes the White House.

“The sign looks like it was taken off the Las Vegas Strip,” said Peter Rizzo, an urban planner. “They are all hideous and not appropriate.”

Smithsonian officials maintain that the NCPC has no authority over signs. Before construction, the museum received approval from the Commission of Fine Arts and the National Capital Planning Commission for the two-year, $30 million renovation. However, the three signs, which cost $72,000, were not added to the plan until last year and were never brought before the agencies. The one attached to the building is temporary and is expected to be removed before 2017.

“We have an honest difference of opinion, based on legal analysis, about whether we need to go to those bodies to get permission to add some signage,” Skorton said at the annual regents forum Dec. 11. “I stand behind the decision to put the signs up, and behind those particular signs.”

A Smithsonian spokeswoman said the institution has not yet responded to the Park Service and it has no further comment.

But Skorton’s attorneys could be wrong, said Peter Byrne, a Georgetown University law professor who teaches historic preservation. Given that the Smithsonian receives substantial federal funding and that its buildings are federal property, Byrne is surprised by the museum’s response.

“I would be very interested to see their legal argument,” Byrne said. “It seems a ridiculous posture to take. They’ve drawn all this attention to themselves.”

The controversy is linked in part to the many layers of regulation in the nation’s capital. As the city’s central planning agency, the NCPC is focused on overall development in the region, and it also serves as the area’s steward of the National Historic Preservation Act. That act requires that changes to historic structures be brought before the public for comment if there is a chance the changes might introduce visual elements that diminish their historic integrity. The three signs did not go through that public review. The CFA advises the federal and District governments on design matters in an effort to preserve the dignity of the capital.

But it is unclear which federal and local laws apply to the Smithsonian. The institution receives major support from the federal government, operates federal buildings and has thousands of federal employees, but it is not technically a federal agency. Rather, it is an organization established by the federal government as a public trust. Its quasi-governmental structure is central to the Smithsonian’s argument that the regulations that apply to federal agencies such as the General Services Administration do not apply to its museums.

“If they were not federal, they would be subject to D.C. regulation and thus reviewable under the Shipstead-Luce Act,” CFA Secretary Thomas Luebke said, referring to a 1930 law that gives the CFA oversight of development around areas of historic importance. If subject to CFA approval, the signs would not be exempt.

Many are calling on the museum complex to reconsider its position. As a cultural organization, the Smithsonian should be a leader in preservation, the critics say.

“I am very disappointed that an agency that receives two-thirds of its budget from the federal government would thumb their nose at Congress,” Rizzo said. “I ask that they go through the deliberative review process just like any other agency. I guarantee the outcome is not going to be favorable, and they sure as hell know that.”

Others say the problem is much bigger than a few signs. Several organizations involved in the ongoing review of the Smithsonian’s Master Plan — a reimagining of a 17-acre parcel surrounding the Smithsonian Castle that was unveiled a year ago — are frustrated with the institution’s slow response to requests for information. The DC Preservation League has gone so far as to file a Freedom of Information Act request for a report on damage from the 2011 earthquake.

“It is a pattern. The Smithsonian Institution doesn’t seem to have a great deal of respect for the process, and it doesn’t feel it needs to comply with it,” said the league’s director, Rebecca Miller. “When they contend their buildings are treasures, I would expect them to behave in that manner.”